<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="js/vue.js"></script>
</head>
<body>
<div id="app">
    <input v-model="count">
    <div v-if="count == 3">div3</div>
    <div v-else-if="count == 4">div4</div>
    <div v-else>div5</div>
    <div v-show="count==3">你好</div>
</div>

<script>
    new Vue({
        el:"#app",
        data(){
            return{
                count:3
            }

        },
        methods:{

        }
    })
</script>

</body>
</html>